algebraic number
- noun
- /ˌæl.dʒəˈbreɪ.ɪk ˈnʌm.bər/
- Specialized
- Mathematicians study algebraic numbers to understand the properties of solutions to polynomial equations.
Examples
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For example, the square root of 2 is an algebraic number because it is a root of the polynomial x^2 - 2.
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Is zero an algebraic number?
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Every integer is an algebraic number because it is a root of a simple polynomial equation.
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The square root of 2 is an algebraic number, as it satisfies the equation x² - 2 = 0.
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Unlike π, which is transcendental, the cube root of 8 is an algebraic number.
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An algebraic number can be expressed as a solution to a polynomial equation.
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An algebraic number is defined as a solution to a polynomial equation, such as x^2 - 2 = 0.
Surface Forms
Morphology
The compound directly combines 'algebraic' (related to algebra) and 'number', so a B1 learner who knows both words would likely infer it refers to a number used in algebra. However, the precise technical definition (a root of a polynomial with rational coefficients) is specialized and not predictable from the constituents alone, so the expression gives a general idea but not the formal meaning.
Etymology
Algebraic number comes from algebraic, the part of math where you solve equations, and number, the value you find; for example, solving x^2 - 2 = 0 gives sqrt(2), the value that makes the equation true. So algebraic number means 'a number that is a solution of an algebra equation'.